Selective signal.



L. W. CARROLL.

SELEGTIVE SIGNAL.

APPLIGATION HLED 00T. 1, 1906.

1,036,796. Paiente Aug. 27, 191.*2.; v I

l fa 25 an acoustic armature ma be vibrated to i "1 iw N l mfr-..- isiiiauais A'LEN'IL OFFICE.

*l l LoUIs wQcAmtoLn or Alamosa, Iowa.4 -l'l ,i snnno'rrvn siGNaLJ 1,036,796. i 'smmcaaonofmaers Patent. Patent-ed Aug.27,1912.

application med october i, 190e. seriaiimsaasoa.

To allwhom it may concern: The object of the invention is to rovide Be it known that I, Louis W. CARROLL, a means for increasing the number o signal citizen of the United States, and resident of stations which may be employed upon a sin- Anamoszn countyof Jones, and State of gle line and for obtaining increased. accu- 5 Iowa, have invented certain new and useful racy inthe operation of devices of this kind. Improvements in Selective Signals, of which In the accompanying drawing there is the following is a specification, and which shown 1n diagram a signalline constructed are illustrated in 4 1the .accompanying draw- 1n accordance' with the invention; ings, forming a'part thereof. i A source of electric energy, as a storage 65 .The ,invention relates to electric signals, battery,'is designated 110, and to this are conand particularly to those. in which provision fnected the wires 11 and 12 of a line circuit is made for calling any1 one of a plurality of comprising a plurality of signal' stations, pfV f stations all served by the same signal line. which three, designated A., B and C, respec It is well known vthat a vperiodic' current tively, areshown. I, 15 having a'given riod ofvibrationl or fre- Signaling apparatus is provided at each 'quencycan only caused to freely traverse of thestations A, B and C, and as shown thqicoils of an electro-magnet having a 'delicomprises. an electroma ,;net` 15 having its nite resistance and number ofturns of wire, coilsvin-circuit with va -branch 1 3 of the line when there is associated withthe magnet an wires 11- and? 12. Preferably the -magnets 75 electric condenser of a .certain capacity. In for all of the signal stations are similar as order to permit aV periodic current having a to resistance and the number of turnsof wire diierent period of vibration, to tra verse the in their coils, and for each of these magnets coils of a similar magnet, a condenser of there is an acoustic armature, as',1 9,2 0V and different capacity is required. .l"urthermore, 21, shown as takngagthe form .of a-ivihrati'le '30 reed, the pitch 'of eheh of the reedsbeing produce an'audible tone i reacted upon by different from that of'all of r4the 'others by an electro-magnet which is excited by a pereason of a ditferencc in length, as shown. riodic current having a period of vibration The coils of each of the electric-magnets which is in harmony with that of t-he arina- 15 are adapted .to the passage of'a 'periodic- 35 39 ture, and i'the magnet is excited by a curcurrent the-"frequent: -of which is 'in.-har' rent having a different. period of vibration monyavi'th therate o` vibration ofthe magthe armature will be affected but little. Ie net armature by means of a' condenser, as is also recognizedthat a resonating tub'ei'nay 16, 17, 18, respectively, preferably cnnected be soundeplbby ayibrating body placed near in series inthe circuit branch 13 with the 90 35 'its mouth if the two'are of similar.-or-"l'armagnet coils. These condensers, as shown,

monic pitch, and that a vibrating body are made ofdiierig capacity by forming placed in the same position with reference each of a diierent number of laminations to the tube but having a diierent 4pitch wi l l Jor plates.

produce little or no sound in the tube. Means are provided for transmitting 95 The invention provides means for e1nthrough the line circuit from the battery- 10 ploying these principles for the purpose of pulsating or alternating currents for oper- -accomplishing so-called selective signaling, ating the signal at any one of the stations and contemplates an electric circuit and a A, B and C. 'Apparatus' for -eifecting this plurality 'of signal stations each in abranch result is preferably locatedl-at a central sta- 10o of the circuit, thebranch circuits being elec tion or lswitchboard D, 'and as shown com'- trically adapted', as by means of condenseie` prises a pluralityl of sendinginstruments d. of differing capacity, for the )assageonly Each .of the instruments d comprises an ofperiodic currents having dchnite periods electro-magnet 25, havinga vbratile'arma- 'of vibration. For each signal station there ture, as 2 8, 29 and 30, each ofthe armatures 10..

is also an acoustic magnet armature having having a rateof. vibration similar to that of a period of vibration in harmony with that one of the acoustic armatures 19,*20 and 21 of the current which may traverse the at the signal stations A, B and C, branch circuit with whichit is to be asso- A .current interrupter. which Preferably' ciated, and a further selection of signals may .takes .the form of a variable. resistance .de- 11o 5" beobtained by .means of a resonating tubevice 27 is controlled by each of'the'niagnet 4:for .each .Q the acoustic armatures. armatures 28, 29 and 3 0, andeach' vices 27 in order that the path for the discharge of the condcnsers 16, 17, 18, may not the branch circuit 13 at one of the signal will then be actuated to produce an audible lvariable resistance devices which is con- '11 to the branches 34, 35, 36, respectively,

- i l A 1,036,796

in a branch, as 34, 35, 36, of the line wire 12, all of the branches leadingvto a switch 37 adapted for closing the line circuit through any. one of them. The coils of the eletro-magnets 25 are served with current. from the battery 10 through that one of the trolled b the armature of the magnet, and preferablyin order to provide apath for the dischag'e of the condensers 1G, 17 and 18`at the several signal stations, each is located in a shunt or branch, as 2 2, 23, 24, of the line circuit. Preferably the circuit branches 22,23, 24, lead from the line Wire of the line wire 12 in front of the switchf37, in order that the circuit may be closed continuously through each of the sending 1ntion, but beyond the variable resistance debe interrupted thereby.-

In practice each of the magnet armatures 28, 29 and 30 at the central station D will be continuously vibrated by the issage of a portion of the current from tue battery 10 through eaclr of the magnets 25 and variable resistance devices 27. In order, however, that but little energy may be consumed in this way.the coils of each of the magnets :2J are designed to afford a high Aimpedance to the passage of the current. Whenever the line circuit is closed through one of the sending instruments d by means of the switch 37, a vibrating current will traverse the line wires 11 and 12, the lperiod of vi-v bration of such current being controlled by the rate of vibration of the armature of the sending instrument then in use. llhe greater portion of this current will traverse only that part of the line circuit including stations to which the current is adapted by reason o condenser, as 16, 17, 18, of the proper capacity, and for the magnet of that branch .13.of the circuit traversed by the currentihere. 'is an acoustic armature tuned to vibrate lat the Vsame rate as the current which the magnet receives. This armature tone, while thearmatures at the other stations will be but little affected, as the magnets of those stations receive but asmall portion of the current and that which they do receive is out of harmony, as to its rate of vibration, with the armatures.

The, tone produced by the magnetic arma. tures at the' several signal stations may be greatly magnified -by Ineansof a resonator, preferably taking the formv o f`a V`tube, es. 31, 32, 33, having a pitch in haranonyf-withv that of the magnet armature atjthe station at which they are located. 'VAS-'showmthe pitch of the several resona'ting tubes is made to correspond( with cthat ofthe mag-v l net armatures at the various stations-by forming the tubes of different size. By means of the resonating tubes a further provision is made for preventing a signal being produced at a station other than that for which it is intended, for while a small amount of a periodic current may traverse the coils of an electro-magnet not adapted to that current by means of a condenser -of the proper capacity, andv although such a current may cause a distinct vibration in, the armature of that-- magnet, such afvibrathe'resonating tube istuned, will not be en hanced and rendered audible thereby. For this reason, .periodic currents,. not widely .tion ofthe armature, not being that to which diiferent as Vto -rate of vibration, may- 'be used for the various signals upon the vSame line, and thel number of' slgnals upon a single line may therefore be= considerable" without requiring a wide range .inthe character of electric curren employed. As all of -the sending instruments d,'n the par-L arrangement of apparatus illus# ticular trated, are in operation continuously 'there' is no danger of a fals signal heilig ternporarily sent overthe `line whenthe switch 'f 37 is first closed, as mi ht occur if itV were necessary to start the vi ration of the Aarma#v tures 28, 29 and v30 at that time.

I claim'as my invcntion- 1. l'n, combination with an electric"'circ11it' having a generator, a transmitting and areceiving electro-magnet connected inY parallel in the circuit, a condenser in series with the' receiving electro-magnet, a tuned Vvibratile arma-ture for each lof the electro-magnets, a variable resistance device in the circuit in front of the transmitting 'electro-magnet,

'and operative connection between the armature of the transmitting electro-magnet and the variable resistance device.

2. ln combination with an" electric circuitl having a generator, a plurality of si naling electro-magnets connected in parallelg inthe circuit, a condenser for each o f such magnets, a plurality of 'branches in one arm of the circuit, a switch 'for controlling the branches, a plurality of electro-magnets each connected in parallel between theother arm of the circuit and one of the branches, al tuned vibratile armature for each of the last-named magnets, and a variable resistance deviceY in each of the Acircuit branches and controlled by one of the vibratile armatures.

3. In, combination, a station circuit including a generator avibrating Icurrent vcon- -troller and an actuating"magnettherefon va linecircuitasignal in the line circuit adapted 4to be ,actuated by I each o Losanna magnet for the vibrating current controller in the station circuit.

4. In combination, an' electriccircuit having a generator and a plurality of signals,

the signals being adapted for actuation by a periodic current having a period of vibration different romthat for actuating all of the others, a plurality of branches in one arm of the circult between the generatorand the signals, a switch controlling the branches,

a vibrator in each of the branches, each of such vibrators being designed to produce a current adapted lfor actuating a different signal, and an electro-magnet for controlf1.5 ling each of the vibrators, one of the magnets being connected in parallel between each of the circuit branches beyond the vibrator from the generator and the other arm ofthe circuit.

"-5. In combination, a generator, a trans- A electro-magnet and the variable resistance device.

6. In combination, a generator, a plurality of transmitting and receiving electromagnets served by the generator, a condenser in' lcircuit with the lcoils of each of the receiving nelectro-magnets, a variable -resistance devlce in circuit with the coils of each of the transmitting electro-magnets, a tuned vibrati1e.armature for each of the receiving electro-magnets, such armatures being of differing pitch, a vibratile armature for each of the transmitting electro-magnets, each of such armatures bemg tuned "in harmony with the armature of one of the re ceiving electro-ma ets, and operative com nection between t e armature of 4each of the transmitting electro-magnets and the variable resistance device in circuit with the coils of the magnet.

l 7. In combination, a station .circuit including a enerator and having a plurality of parallel) ranches,avibratin currentcontroller'in veach branch of sai circuit, :mid4

current controllers havin vibration riods of different frequency, aine circuit aving a corresponding number of parallel branches, a signal adapted to be actuated --by a periodic current in each branch of theline circuit, eachof said signals being adapted to be actuated-by a perlodic current having a frequency corresponding to the frequency of one of the current controllers and means for connecting the line circuit in shunt with any one of the said branches of the station circuit.

LOUIS W. CARROLL. Witnesses CHARLES B.' GILnsoN, E. M. KLA'mHEn. 

